1. Field of the Invention
The present invention relates to an inductor device and a method of manufacturing the same and, more particularly, an inductor device including such a structure that a planar type inductor is formed on a wiring substrate, or the like and a method of manufacturing the same.
2. Description of the Related Art
In the prior art, there is the inductor device which is used in the high-frequency circuit, and the like in various electronic equipments. As the structure of the inductor, there is the winding wire type in which the electrical wire is wound, or the planar type in which the spiral coil conductor is formed on a plane, and the like.
In Patent Literature 1 (Patent Application Publication (KOKAI) 2001-102235), the planar type magnetic element is disclosed, and it is set forth that the magnetic element is constructed by stacking the insulating layer and the magnetic body layer on the planar coil in which the groove portion between adjacent coil conductors has a groove aspect ratio of 1 or more.
In Patent Literature 2 (Patent Application Publication (KOKAI) 2008-10695, Patent Literature 3 (Patent Application Publication (KOKAI) Hei 6-132131), Patent Literature 4 (Patent Application Publication (KOKAI) Hei 11-354323), and Patent Literature 5 (Patent Application Publication (KOKAI) 2008-205179), it is set forth that a high-frequency loss is reduced by providing the slits to the magnetic layer in the inductor. For more detail, in Patent Literature 2, it is disclosed that the substantially <-shaped slit that spreads from the bending portion to the outer peripheral direction is provided to the magnetic body layer. In Patent Literature 3, it is disclosed that the slits of the magnetic thin film are provided in parallel with the direction along which the coil conductor extends.
Also, in Patent Literature 6 (Patent Application Publication (KOKAI) 2002-80973), it is set forth that, in the method of forming the fine pattern plating film having the soft magnetic characteristic by the electroless plating, such a method is described that minute amount of organic stabilizer is added into the electroplating bath so as to form a homogeneous electroless plating film in the pattern portion, and the impurities in the plating bath are removed and also the adequate stirring is applied continuously.
In the case that the inductor component of the winding wire type is mounted on the wiring substrate, a height and a mounting area must be secured to some extent and thus a size reduction is restricted. Also, a cost of such inductor component is relatively high, and thus it is possible that an increase in production cost is caused.
Further, in order to make the inductor component respond to the higher frequency trend, the special structure is needed, e.g., the air core structure is required, or the like. Hence, an additional cost is required to design the dedicated component.
As the countermeasures for this, in order to attain a size reduction and a cost reduction of the electronic equipment, there is the method that the inductor element is built into the wiring substrate. However, according to this method, such problems existed that the EMI (undesirable radiation) noise is emitted from the inductor element or the sufficient characteristics of the inductor element cannot be obtained, so that the reliability of the inductor element is not always satisfactory.
As a result, the technology to build the highly reliable inductor element having the desired characteristics into the wiring substrate is earnestly desired.